Improvement in making plow-plates from molten steel



UNITED STATES PATENT Ormea.

F. Fi SMITH, OF MOMENOE, ILLINOIS.

IMPROVEMENT IN MAKING PLOW-PLATES FROM IVIOLTEN STEEL.

Specilication Ibrmingpart of Letters Patent No. 30,691, dated November20, 1860.

To all whom it may concern: the other parts. Fig. 7 is a perspectiveView Be it known that I, F. F. SMITH, of Moof the casting constitutingthe moldboard O mence, in the county of Kankakee and State and standardB. Fig. Sis a perspective view of Illinois, have invented a new anduseful of the landside D. Improvement in Steel Flows; and I do herebyrIhe casting B O is made with a flange, a, at declare that the followingis a full, clear, and the foot and back of the standard for the atexactdescription of the same, reference being tachment of the landside D byrivets or bolts had to the accompanying drawings, forming b b,countersunk on the outside of D, said part of this specification. flangebeing thrown back under the mold- All steel plows heretofore known orused board, as shown in Figs. 3 and 4, to enable have beeninade of plateor rolled steel worked the landside to be brought fiush with the intoshape by bending, welding, and other standard and corresponding edge ofthe share. forging operations, and owing to the difleulr The saidcasting I3 C is also made with a ties which present themselves in thismode of fiange, c, of similar character to a in front of manufacturingthem have not only had many the standard, and has a rabbet, d, (seeFigs. serious defects, but have been very expensive. 2, 3, and 4,)formed along its front or lower One of the greatest defects has beenthat the edge, that the back or upper edge of the share parts have beenmade of nearly equal thickmay lap over it in such manner that the facesness, and as the wear comes most on the botof the mold-board and sharecome together tom and pointthose partshave been frequently with a flushjoint. rlhe share is secured by worn out by use, while the mold-boardhas rivets or bolts e e passing through the rabbeen barely polished.Another defect has bet dandcountersunk on the outside. Each arisen fromthe diflieulty of fashioning the casting is made by pouring the moltensteel parts to the exact shape desired, owing to from a crncible orother vessel into a "mold theirhaving been ofnecessityformed byhand,whose cavity is of the desired form. The no system of dies having beenfound suitable I molds are made of cast-iron. for the purpose. I I donot consider it necessary for the iu- The object of my invention is tomake a struction of those skilled in the art of casting steel plow freefrom such defects at a greatly l metals to explain the form andconstruction I reduced cost; and to this end my invention of theseiron-molds further than to make the consists in the manufacture oftheplow-that following remarks, viz: first, that the tube is to say, thoseparts of it commonly made of formed for the reception of the moltensteel steel-viz., the share, the landside, and the and its conveyance tothe cavity of the mold mold-board--by pouring the steel in a moltenshould be so arranged that the steel will not state into molds of therequired shape, by strike upon the interior surface of the cavity,

which process I am enabled to proportion the but will flow into it fromone side, for in striki thickness of the several parts to the work anding upon any portion of the interior surface wear to which they aresubject, and to obtain it will cut or melt away that portion andrenexactly and infallibly the form desired. der the mold worthless afterone or two cast- In the manufacture of the molded steel plow ings havebeen made second, that the ventila- I propose, for the sake of greaterconvenience tion of the mold should be made by extremely of casting, aswell as of insuring the greater narrow openings, which will prevent thesteel solidity of the metal and freedom from honescaping, but yet permitthe escape of the air. ey-comb,77 to make it of two or more castings.These openings I make` by placing pieces of The accompanying drawingsrepresent a thin hoop-iron between the joints of the mold plow whoseshare A is made of one casting, or by making very shallow grooves in theits mold-board B and standard O of another, faces of the joints. and itslandside D of a third. The molded cast-steel plow, when the east-Figuresi and 2 are opposite side views of ing is effected in iron molds,possesses anthe plow. Fig. 3 is a back view of the same. other advantagenot stated in the commence Fig. 4l is a bottom view of the same. Fig. 5ment of this s])ecificationthat is to say, by is a top view of the same.Fig. 6 is a perbeing chilled in the casting it becomes so hard spectiveview of the share A separate from as to be capable of wearing for a verylong time. It is necessary, as soon as the steel is vpoured into themolds, and before the metal has cooled enough to contract, to` open themolds and detach the casting from the sprue, because if not detachedbefore the shrinkage takes place the plate is apt to crack. The iiangesand undercut parts of the plates, too, cling to the parts of the moldswhere they receive their peculiar forms, and not being able to shrink inall directions in cooling require the utmost care in freeing the castingfrom the sprue and molds. The molds themselves being of iron cannotyield to compensate for shrinkage, and hence I open the molds as soonvas the metal is poured into them. It is important, also, that the moldsbe ventilated to allow the gases to escape. This Vl". accomplish eitherby the permanent openings at the joints of the mold or by drivingin-thin pieces of metal or other material at the joint to raise orseparate the molds slightly. The clamps for securing the molds should beso made and united as to be readily detached, as the utmost expeditionmust be had in raising the mold to detach the sprue from the plate.

The steel used may be that of commerce, and in case of its being of ahigh quality7 it may be reduced by mixing with it a portion of iron. Todetermine when the steel is sufiiciently limped or fluid to pour intothe molds, a rod of iron is inserted in the molten steel, and by thequantity of steel that adheres to the rod its iluidity may be correctlyascertained, the smaller the. quantity of steel that adheres to .seenfrom the the rod the more suitable its condition for being poured intothe. molds. It will thus be nicety with which each and every ope-rationmust be watched and attended to that the casting of steel plates forplows, which have varied forms and thicknesses, is entirely differentfrom that of casting iron in molds.

Heretofore in casting articles of steel in iron molds the molds werefirst highly heated, and after the metal was poured into them they were,

, with their metal in them, put into an oven or furnace and heated uptoa cherry-red heat, and then allowed to cool gradually to preventcracking by shrinkage. VThis process so anneals and softens the steel asto make it comparatively of little value for plow -plates, While itgreatly adds to the expense of making the plates. The contour of themold gives the form to the plow-plate, and this form may be varied tosuit the fashion of the plows to be made, or the particular partsthereof that are to be made of steel.

What I claim as my invention, and desire to secure by Letters Patent,is-v Making plow-plates of irregular forms and of variable thicknessesby pouring molten steel into iron molds in the manner. and for thepurposes herein set forth.

F. F. SMITH.

Vitne-sses:

NOAH R. L. BRIs'ror., Anson W. BRISTOL.

